1. Field of the Invention
The present invention is directed to a watercraft, and more particularly to a water preclusion and sound attenuation system employed in an induction system for a watercraft engine.
2. Description of Related Art
Personal watercraft have become increasingly popular in recent years. This type of watercraft is sporting in nature; it turns swiftly, it is easily maneuverable, and accelerates quickly. A personal watercraft today commonly carries one rider and up to three passengers. Typically, the rider and passengers sit on a straddle-type seat that is formed by the hull of the watercraft. The straddle-type seat is generally aligned with the longitudinal axis of the hull. The space beneath the straddle-type seat is usually used as an engine compartment for supporting the engine within the watercraft. The engine is preferably arranged within the engine compartment so that the crankshaft of the engine is aligned with the longitudinal axis of the watercraft. With the engine arranged as such, the crankshaft of the engine may be directly connected to an output shaft for driving a propulsion unit. Additionally, such an arrangement allows the engine to be arranged within the seat pedestal. Arranged as such, the engine and seat pedestal form a compact unit. During operation, the engine and any passengers straddle the seat as well as the engine while they are seated on the straddle-type seat. With the hull shaped as such, the engine is in close spacing with the passengers during operation, thus allowing the overall size of the watercraft to remain quite small, resulting in a compact and highly maneuverable watercraft.
One problem caused by the speed and maneuverability of these watercraft is that waterspray generated by the contact of the hull with the body of water in which the watercraft is operating causes water to spray upwardly onto the upper deck portion of the watercraft. Such waterspray increases the flow of water into the ventilation openings usually disposed on the upper deck of these watercraft. Such a flow of water into the ventilation openings can cause several problems. For example, a significant flow of water droplets into the ventilation openings can accumulate and eventually puddle in the bottom of the engine compartment within the watercraft. As the watercraft maneuvers, such puddled water sloshes within the engine compartment and may enter various components of the engine, such as, but without limitation, the induction system. Additionally, water which sloshes and comes into contact with hot engine components, can vaporize and flow into the induction system and the combustion chambers within the engine. Thus, it is desirable to construct an induction system which reduces the amount of water vapors introduced into the combustion chambers of the engine.
Another difficulty faced by owners of personal watercraft is that, at least partially in response to the noise generated by personal watercraft, certain recreational facilities have banned the operation of most personal watercraft.
According to one aspect of the present invention, a watercraft comprises a hull having a lower portion and an upper deck portion, an engine disposed within the hull which includes at least one combustion chamber and a body occupying a substantial volume of space within the engine compartment and is spaced from the engine. The watercraft also includes an induction system configured to guide air into the combustion chamber of the engine for combustion therein. The inlet to the induction system opens into the engine compartment and is disposed over the body.
By arranging the inlet to the induction system over the body, the watercraft according to the present invention reduces the likelihood that water present within the engine compartment can splash into the inlet of the induction system. Thus, the likelihood that the engine is damaged from water within the engine compartment is also reduced.
According to another aspect of the present invention, a watercraft includes a hull having a lower portion and an upper deck portion and an engine compartment defined within the hull. An engine is disposed within the engine compartment and includes at least one combustion chamber therein. The watercraft also includes an induction system configured to guide air into the combustion chamber for combustion therein. The induction system includes an inlet opening into the engine compartment. A splash guard is positioned adjacent the inlet and configured to prevent water within the engine compartment from splashing into the inlet. Preferably, the splash guard extends beneath the inlet so as to reduce the amount of water from the lower surface of the engine compartment that may splash into the inlet.
According to yet another aspect of the present invention, a watercraft includes a hull having a lower portion and an upper deck portion and an engine compartment defined within the hull. An engine is disposed within the engine compartment and includes at least one combustion chamber having an intake port. An induction system is configured to guide air into the combustion chamber for combustion therein and includes a vapor separator disposed within the hull so as to be not directly above the engine.
Another aspect of the present invention includes the realization that performance of a vapor separator within the engine compartment of a watercraft can be improved if the vapor separator is not positioned directly above the engine. For example, as a vapor separator operates, to reduce an amount of water vapor within an air supply, heat added or conducted into the vapor separator raises the vapor pressure of the water therein, thus reducing the effectiveness of the vapor separator to remove water from an airflow passing therethrough. Heat from the engine can be conducted into the vapor separator by radiation and/or convection. Thus, by positioning the vapor separator so as not to be directly over the engine, heat conducted into the vapor separator from the engine is thereby attenuated, thus improving the performance of the vapor separator. Thus, more water vapor is separated from air entering the induction system thereby further protecting the engine and improving combustion conditions within the combustion chamber.
Further aspects, features, and advantages of the present invention will become apparent from the detailed description of the preferred embodiments which follows.